Portable power supply



FIG. 1 is a first perspective view of a portable power supply showingour new design;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof;

FIG. 8 is a bottom view thereof;

FIG. 9 is a perspective view of another state of the portable powersupply thereof; and,

FIG. 10 is an enlarged view of the selected portion 10 in FIG. 2 .

The broken lines shown in the drawings depict portions of the portablepower supply that form no part of the claimed design.

CLAIM The ornamental design for a portable power supply, as shown anddescribed.